How did you get from, "thoughts are the brains translations of all stimuli simultaneously" to "so its quite possible that mind might have more than just the aspect of observation"?
The Mind "Observes" and The Physical "Takes Action".
Memory is thought about the past. If we already know that The Brain is thinking (neuron communication) and that the mind is observing, then the mind cannot contain memory (thoughts of past).
Why would "past" and "present" be duality? Present is happening NOW. You can observe it. Past and Future you have to actually "think" about with the brain, so yes, "Past" and "Future" would be duality, not "Now".
In the beginning you already said that you believe that everything is mind energy. If this is true, then the brain must be a part of mind energy, too, which it is. The mind is just aware of the "functioning" of the brain (the thoughts), but it is the actual brain which think thoughts about the past which we call memory. The mind is aware of now, and aware of the thoughts of the past and future being thought NOW - The mind is always present observing now - but it can give the illusion of observing the past or future if those thoughts are being thought by the brain NOW.
I already explained "who" or "what" the observer is in the original post, and there is no such thing as "separation" as I already explained in the original post of this thread.